Recovery Animals in Toxicology Studies: An Innovation and Quality Consortium Perspective on Best Practices With Case Study Examples.

The inclusion of recovery animals in nonclinical safety studies that support clinical trials is undertaken with a wide diversity of approaches even while operating under harmonized regulatory guidance. While empirical evaluation of reversibility may enhance the overall nonclinical risk assessment, there are often overlooked opportunities to reduce recovery animal use by leveraging robust scientific and regulatory information. In the past, there were several attempts to benchmark recovery practices; however, recommendations have not been consistently applied across the pharmaceutical industry. A working group (WG) sponsored by the 3Rs Translational and Predictive Sciences Leadership Group of the IQ Consortium conducted a survey of current industry practice related to the evaluation of reversibility/recovery in repeat dose toxicity studies. Discussion among the WG representatives included member company strategies and case studies that highlight challenges and opportunities for continuous refinements in the use of recovery animals. The case studies presented in this paper demonstrate increasing alignment with the Society of Toxicologic Pathology recommendations (2013) towards (1) excluding recovery phase cohorts by default (include only when scientifically justified), (2) minimizing the number of recovery groups (e.g., control and one dose level), and (3) excluding controls in the recovery cohort by leveraging external and/or dosing phase data. Recovery group exclusion and decisions regarding the timing of reversibility evaluation may be driven by indication, modality, and/or other scientific or strategic factors using a weight of evidence approach. The results and recommendations discussed present opportunities to further decrease animal use without impacting the quality of human risk assessment.

Non-Human Primate Husbandry and Impact on Non-Human Primates Health: Outcomes From an IQ DruSafe/3RS Industrial Benchmark Survey.

The presence of health issues (diarrhea, poor body condition) in non-human primates can impact animal welfare, confound toxicity study data, and lead to animal exclusion from studies. A working group cosponsored by DruSafe and 3Rs Translational and Predictive Sciences Leadership Groups of the IQ Consortium conducted a survey to benchmark quarantine, pre-study screening, husbandry, and veterinary care practices and their impact on NHP health. Nineteen companies participated in the survey providing separate responses for studies conducted in-house and at Contract Research Organizations from 3 regions (North America (NA), Europe and Asia) for an aggregate of 33 responses. A majority of responding companies conducted studies at North America CROs (39%) or in-house (36%) using primarily Chinese (33%) or Cambodian (27%) and to a lesser extent Vietnam (18%) or Mauritian (15%) origin NHPs. Forty-Five percent of responses had pre-study health issues (fecal abnormalities, etc.) on ≥ 1 studies with the highest incidence observed in Vietnam origin NHPs (80%). The survey suggested variable pre-screening and quarantine practices across facilities. Husbandry practices including behavioral assessments, environmental enrichment and consistent diets were associated with a lower incidence of health issues. The survey also benchmarked approaches used to diagnose and manage abnormal feces in NHPs and has provided strategies to minimize impact on NHP health. The survey highlighted opportunities for harmonizing screening criteria across industry and for improving tracking and sharing of health screening results, leading to further refinement of NHP veterinary care practices, higher quality studies, and reduced NHP use.

Toxicologic Pathology Forum: Opinion on Not Euthanizing Control Animals in the Recovery Phase of Non-Rodent Toxicology Studies.

Nonclinical toxicology studies that are required to support human clinical trials of new drug candidates are generally conducted in a rodent and a non-rodent species. These studies typically contain a vehicle control group and low, intermediate, and high dose test article groups. In addition, a dosing-free recovery phase is sometimes included to determine reversibility of potential toxicities observed during the dosing phase and may include additional animals in the vehicle control and one or more dose groups. Typically, reversibility is determined by comparing the test article-related changes in the dosing phase animals to concurrent recovery phase animals at the same dose level. Therefore, for interpretation of reversibility, it is not always essential to euthanize the recovery vehicle control animals. In the absence of recovery vehicle control tissues, the pathologist's experience, historical control database, digital or glass slide repositories, or literature can be used to interpret the findings in the context of background pathology of the species/strain/age. Therefore, in most studies, the default approach could be not to euthanize recovery vehicle control animals. This article provides opinions on scenarios that may or may not necessitate euthanasia of recovery phase vehicle control animals in nonclinical toxicology studies involving dogs and nonhuman primates.

Novel Interaction of Class IIb Histone Deacetylase 6 (HDAC6) with Class IIa HDAC9 Controls Gonadotropin Releasing Hormone (GnRH) Neuronal Cell Survival and Movement.

The impact of histone deacetylases (HDACs) in the control of gonadotropin releasing hormone (GnRH) neuronal development is unknown. We identified an increase in many HDACs in GT1-7 (differentiated) compared with NLT (undifferentiated) GnRH neuronal cell lines. Increased HDAC9 mRNA and protein and specific deacetylase activity in GT1-7 cells suggested a functional role. Introduction of HDAC9 in NLT cells protected from serum withdrawal induced apoptosis and impaired basal neuronal cell movement. Conversely, silencing of endogenous HDAC9 in GT1-7 cells increased apoptosis and cell movement. Comparison of WT and mutant HDAC9 constructs demonstrated that the HDAC9 pro-survival effects required combined cytoplasmic and nuclear localization, whereas the effects on cell movement required a cytoplasmic site of action. Co-immunoprecipitation demonstrated a novel interaction of HDAC9 selectively with the Class IIb HDAC6. HDAC6 was also up-regulated at the mRNA and protein levels, and HDAC6 catalytic activity was significantly increased in GT1-7 compared with NLT cells. HDAC9 interacted with HDAC6 through its second catalytic domain. Silencing of HDAC6, HDAC9, or both, in GT1-7 cells augmented apoptosis compared with controls. HDAC6 and -9 had additive effects to promote cell survival via modulating the BAX/BCL2 pathway. Silencing of HDAC6 resulted in an activation of movement of GT1-7 cells with induction in acetylation of α-tubulin. Inhibition of HDAC6 and HDAC9 together resulted in an additive effect to increase cell movement but did not alter the acetylation of αtubulin. Together, these studies identify a novel interaction of Class IIa HDAC9 with Class IIb HDAC6 to modulate cell movement and survival in GnRH neurons.

Helex device closure of multiple atrial septal defects.

OBJECTIVES: To describe the effectiveness of the Helex Septal Occluder (HSO) to close multiple atrial septal defects (mASDs). Background : Limited information is available describing closure of mASDs with the HSO. METHODS: A total of 28 patients who underwent closure of mASDs with the HSO were identified by retrospective review of our catheterization database between 2001 and 2012. Procedural details and follow up information were collected. RESULTS: Median age was 19.2 years, median weight 48 kg, with 10 (36%) patients weighing <25 kg. Indication for closure was RV enlargement (RVE) in all patients and additionally neurologic events occurred in 3/28 (11%). Median stop-flow diameter for the largest ASD was 14 (4-23) mm. One HSO was implanted in 21/28 (75%), 2 in 6/28 (21%), and 3 in 1/28 (4%). One embolization and one transient arrhythmia occurred with no sequelae. Immediate residual shunt was absent in 5/28 (18%), trivial in 15/28 (54%), small in 6/28 (21%), and moderate in 2/28 (7%). Of the 25 patients with ≥6 months follow-up (median 53 months), residual shunt was absent in 13/25 (52%), trivial in 5/25 (20%), and small in 7/25 (28%). RVE resolved in all but one patient with no other associated lesions and ≥6 months of follow-up. No patient with prior neurological event had recurrence at last follow-up. CONCLUSIONS: We conclude that closure of mASDs with ≥1 HSO is effective with a low complication rate. The ability of HSO devices to overlap or sandwich each other may facilitate safe implantation of multiple devices in smaller patients.

Exposure of neonatal rats to the endocrine disrupter Bisphenol A affects ontogenic expression pattern of testicular steroid receptors and their coregulators.

In light of the adverse reports of Bisphenol A (BPA) on reproduction and considering the pivotal role played by the steroid receptors (SRs) and their coregulators in male reproduction, it was of interest to decipher the influence that BPA may have on their expression pattern during critical 'windows' of development. Male rats were injected with 2.4 µg per pup per day of BPA from postnatal days (PND) 1-5 and controls received vehicle. During development, the testicular expression pattern of SRs (AR, ERß and ERα), coactivators (SRC-1, SRC-2 and SRC-3) and corepressors (NCoR and SMRT) in BPA-exposed rats were compared. A significant decrease in the expression of SRs was seen in the BPA group. SRC-1 showed a significant decrease, whereas SRC-2 and SRC-3 showed a significant increase in the protein expression whereas corepressor expression remained unaltered in the BPA-exposed groups. Such impairments in the expression pattern can be a putative mechanism of adversities on fertility as a result of BPA exposure.

Beyond MABEL: An Integrative Approach to First in Human Dose Selection of Immunomodulators by the Health and Environmental Sciences Institute (HESI) Immuno-Safety Technical Committee (ITC).

Administration of a new drug candidate in a first-in-human (FIH) clinical trial is a particularly challenging phase in drug development and is especially true for immunomodulators, which are a diverse and complex class of drugs with a broad range of mechanisms of action and associated safety risks. Risk is generally greater for immunostimulators, in which safety concerns are associated with acute toxicity, compared to immunosuppressors, where the risks are related to chronic effects. Current methodologies for FIH dose selection for immunostimulators are focused primarily on identifying the minimum anticipated biological effect level (MABEL), which has often resulted in sub-therapeutic doses, leading to long and costly escalation phases. The Health and Environmental Sciences Institute (HESI) - Immuno-Safety Technical Committee (ITC) organized a project to address this issue through two complementary approaches: (i) an industry survey on FIH dose selection strategies and (ii) detailed case studies for immunomodulators in oncology and non-oncology indications. Key messages from the industry survey responses highlighted a preference toward more dynamic PK/PD approaches as in vitro assays are seemingly not representative of true physiological conditions for immunomodulators. These principles are highlighted in case studies. To address the above themes, we have proposed a revised decision tree, which expands on the guidance by the IQ MABEL Working Group (Leach et al. 2021). This approach facilitates a more refined recommendation of FIH dose selection for immunomodulators, allowing for a nuanced consideration of their mechanisms of action (MOAs) and the associated risk-to-benefit ratio, among other factors.

The matricellular protein CCN1/Cyr61 is a critical regulator of Sonic Hedgehog in pancreatic carcinogenesis.

CCN1 is a matricellular protein and a member of the CCN family of growth factors. CCN1 is associated with the development of various cancers including pancreatic ductal adenocarcinoma (PDAC). Our recent studies found that CCN1 plays a critical role in pancreatic carcinogenesis through the induction of EMT and stemness. CCN1 mRNA and protein were detected in the early precursor lesions, and their expression intensified with disease progression. However, biochemical activity and the molecular targets of CCN1 in pancreatic cancer cells are unknown. Here we show that CCN1 regulates the Sonic Hedgehog (SHh) signaling pathway, which is associated with the PDAC progression and poor prognosis. SHh regulation by CCN1 in pancreatic cancer cells is mediated through the active Notch-1. Notably, active Notch-1is recruited by CCN1 in these cells via the inhibition of proteasomal degradation results in stabilization of the receptor. We find that CCN1-induced activation of SHh signaling might be necessary for CCN1-dependent in vitro pancreatic cancer cell migration and tumorigenicity of the side population of pancreatic cancer cells (cancer stem cells) in a xenograft in nude mice. Moreover, the functional role of CCN1 could be mediated through the interaction with the αvß3 integrin receptor. These extensive studies propose that targeting CCN1 can provide a new treatment option for patients with pancreatic cancer since blocking CCN1 simultaneously blocks two critical pathways (i.e. SHh and Notch1) associated with the development of the disease as well as drug resistance.

Cysteine-rich 61-connective tissue growth factor-nephroblastoma-overexpressed 5 (CCN5)/Wnt-1-induced signaling protein-2 (WISP-2) regulates microRNA-10b via hypoxia-inducible factor-1α-TWIST signaling networks in human breast cancer cells.

MicroRNAs (miRNAs) are naturally occurring single-stranded RNA molecules that post-transcriptionally regulate the expression of target mRNA transcripts. Many of these target mRNA transcripts are involved in regulating processes commonly altered during tumorigenesis and metastatic growth. These include cell proliferation, differentiation, apoptosis, migration, and invasion. Among the several miRNAs, miRNA-10b (miR-10b) expression is increased in metastatic breast cancer cells and positively regulates cell migration and invasion through the suppression of the homeobox D10 (HOXD10) tumor suppressor signaling pathway. In breast metastatic cells, miR-10b expression is enhanced by a transcription factor TWIST1. We find that miR-10b expression in breast cancer cells can be suppressed by CCN5, and this CCN5 effect is mediated through the inhibition of TWIST1 expression. Moreover, CCN5-induced inhibition of TWIST1 expression is mediated through the translational inhibition/modification of hypoxia-inducible factor-1α via impeding JNK signaling pathway. Collectively, these studies suggest a novel regulatory pathway exists through which CCN5 exerts its anti-invasive function. On the basis of these findings, it is plausible that reactivation of CCN5 in miR-10b-positive invasive/metastatic breast cancers alone or in combination with current therapeutic regimens could provide a unique, alternative strategy to existing breast cancer therapy.

Rapid-onset hypogonadism secondary to crizotinib use in men with metastatic nonsmall cell lung cancer.

BACKGROUND: The objective of this study was to document the differences in testosterone (T) levels between crizotinib-treated and noncrizotinib-treated patients with metastatic nonsmall cell lung cancer (NSCLC). METHODS: Testosterone levels were measured in 19 men with metastatic NSCLC who received crizotinib and in 19 men with metastatic NSCLC who did not receive crizotinib. Clinical characteristics of the patients were compared, and additional hormone assays were performed as appropriate. Two patients who began crizotinib and 4 patients who had dose interruptions or who stopped crizotinib therapy had serial hormone measurements, permitting the documentation of dynamic hormone changes on and off crizotinib treatment. RESULTS: Total T levels were low (<241 ng/dL) in 19 of 19 (100%) crizotinib-treated men and in 6 of 19 men (32%) with metastatic NSCLC who did not receive crizotinib (mean T levels, 131 ng/dL and 311 ng/dL, respectively; P = .0002). Only 1 in 5 patients who had anaplastic lymphoma kinase (ALK) gene rearrangements and had not yet received crizotinib had low T. The initiation of crizotinib in 2 patients who had previously normal T levels was associated with a rapid decreases in T and in luteinizing hormone and follicle stimulating hormone levels within 14 to 21 days. Discontinuation of crizotinib led to increases back to normal T levels. CONCLUSIONS: Crizotinib therapy caused rapid suppression of T levels in men. The current results indicated that the site of action must include a central (hypothalamic or pituitary) effect, but additional direct testicular effects could not be excluded. Further work is required to assess the correlation between low T levels and crizotinib side effects as well as the exact molecular mechanism and site of drug toxicity.

Cyr61/CCN1 signaling is critical for epithelial-mesenchymal transition and stemness and promotes pancreatic carcinogenesis.

BACKGROUND: Despite recent advances in outlining the mechanisms involved in pancreatic carcinogenesis, precise molecular pathways and cellular lineage specification remains incompletely understood. RESULTS: We show here that Cyr61/CCN1 play a critical role in pancreatic carcinogenesis through the induction of EMT and stemness. Cyr61 mRNA and protein were detected in the early precursor lesions and their expression intensified with disease progression. Cyr61/CCN1 expression was also detected in different pancreatic cancer cell lines. The aggressive cell lines, in which the expressions of mesenchymal/stem cell molecular markers are predominant; exhibit more Cyr61/CCN1 expression. Cyr61 expression is exorbitantly higher in cancer stem/tumor initiating Panc-1-side-population (SP) cells. Upon Cyr61/CCN1 silencing, the aggressive behaviors are reduced by obliterating interlinking pathobiological events such as reversing the EMT, blocking the expression of stem-cell-like traits and inhibiting migration. In contrast, addition of Cyr61 protein in culture medium augments EMT and stemness features in relatively less aggressive BxPC3 pancreatic cancer cells. Using a xenograft model we demonstrated that cyr61/CCN1 silencing in Panc-1-SP cells reverses the stemness features and tumor initiating potency of these cells. Moreover, our results imply a miRNA-based mechanism for the regulation of aggressive behaviors of pancreatic cancer cells by Cyr61/CCN1. CONCLUSIONS: In conclusion, the discovery of the involvement of Cyr61/CCN1 in pancreatic carcinogenesis may represent an important marker for PDAC and suggests Cyr61/CCN1 can be a potential cancer therapeutic target.

Tumor cell-derived PDGF-B potentiates mouse mesenchymal stem cells-pericytes transition and recruitment through an interaction with NRP-1.

BACKGROUND: New blood vessel formation, or angiogenic switch, is an essential event in the development of solid tumors and their metastatic growth. Tumor blood vessel formation and remodeling is a complex and multi-step processes. The differentiation and recruitment of mural cells including vascular smooth muscle cells and pericytes are essential steps in tumor angiogenesis. However, the role of tumor cells in differentiation and recruitment of mural cells has not yet been fully elucidated. This study focuses on the role of human tumor cells in governing the differentiation of mouse mesenchymal stem cells (MSCs) to pericytes and their recruitment in the tumor angiogenesis process. RESULTS: We show that C3H/10T1/2 mouse embryonic mesenchymal stem cells, under the influence of different tumor cell-derived conditioned media, differentiate into mature pericytes. These differentiated pericytes, in turn, are recruited to bind with capillary-like networks formed by endothelial cells on the matrigel under in vitro conditions and recruited to bind with blood vessels on gel-foam under in vivo conditions. The degree of recruitment of pericytes into in vitro neo-angiogenesis is tumor cell phenotype specific. Interestingly, invasive cells recruit less pericytes as compared to non-invasive cells. We identified tumor cell-secreted platelet-derived growth factor-B (PDGF-B) as a crucial factor controlling the differentiation and recruitment processes through an interaction with neuropilin-1 (NRP-1) in mesenchymal stem cells. CONCLUSION: These new insights into the roles of tumor cell-secreted PDGF-B-NRP-1 signaling in MSCs-fate determination may help to develop new antiangiogenic strategies to prevent the tumor growth and metastasis and result in more effective cancer therapies.

Crocetin inhibits pancreatic cancer cell proliferation and tumor progression in a xenograft mouse model.

Crocetin, a carotenoid compound derived from saffron, has long been used as a traditional ancient medicine against different human diseases including cancer. The aim of the series of experiments was to systematically determine whether crocetin significantly affects pancreatic cancer growth both in vitro and/or in vivo. For the in vitro studies, first, MIA-PaCa-2 cells were treated with crocetin and in these sets of experiments, a proliferation assay using H(3)-thymidine incorporation and flow cytometric analysis suggested that crocetin inhibited proliferation. Next, cell cycle proteins were investigated. Cdc-2, Cdc-25C, Cyclin-B1, and epidermal growth factor receptor were altered significantly by crocetin. To further confirm the findings of inhibition of proliferation, H(3)-thymidine incorporation in BxPC-3, Capan-1, and ASPC-1 pancreatic cancer cells was also significantly inhibited by crocetin treatment. For the in vivo studies, MIA-PaCa-2 as highly aggressive cells than other pancreatic cancer cells used in this study were injected into the right hind leg of the athymic nude mice and crocetin was given orally after the development of a palpable tumor. The in vivo results showed significant regression in tumor growth with inhibition of proliferation as determined by proliferating cell nuclear antigen and epidermal growth factor receptor expression in the crocetin-treated animals compared with the controls. Both the in vitro pancreatic cancer cells and in vivo athymic nude mice tumor, apoptosis was significantly stimulated as indicated by Bax/Bcl-2 ratio. This study indicates that crocetin has a significant antitumorigenic effect in both in vitro and in vivo on pancreatic cancer.

Correction to: Behavioral Artistry: Examining the Relationship Between the Interpersonal Skills and Effective Practice Repertoires of Applied Behavior Analysis Practitioners.

The article Behavioral Artistry: Examining the Relationship Between the Interpersonal Skills and Effective Practice Repertoires of Applied Behavior Analysis Practitioners, written by Kevin Callahan, was originally published electronically on the publisher's internet portal (currently SpringerLink) on August 29, 2019 without open access. With the author(s)' decision to opt for Open Choice the copyright of the article changed on August, 2019 to © The Author(s) 2019 and the article is forthwith distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, duplication, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

Behavioral Artistry: Examining the Relationship Between the Interpersonal Skills and Effective Practice Repertoires of Applied Behavior Analysis Practitioners.

This study investigated interpersonal skills associated with the concept of behavioral artistry (BA), a repertoire of practitioner behaviors including care, attentiveness, and creativity, among others, associated with the effective delivery of applied behavior analysis (ABA) treatment. Survey results indicated parents of children with autism preferred BA descriptors for ABA therapists over non-BA descriptors. A separate survey of 212 university students on a standardized personality assessment revealed students majoring and/or working in the field of ABA had lower levels of BA than those in other human services professions. Practitioners with higher BA scores were observed and rated more positively in their delivery of ABA for children with autism. Implications for training/supervising effective ABA practitioners within a BA model are discussed.

Arterial Thickness and Stiffness Are Independently Associated with Left Ventricular Strain.

BACKGROUND: The aim of this study was to examine the association between myocardial strain and arterial thickness and stiffness in young adults. Increased common carotid artery intima media thickness and peripheral arterial stiffness are known to precede coronary artery disease and cardiovascular (CV) events such as myocardial infarction and congestive heart failure. However, subclinical cardiac dysfunction can be detected in high-risk adults by myocardial strain echocardiography. The authors hypothesized that increased carotid artery intima media thickness would be associated with abnormal myocardial strain in young subjects who had obesity and type 2 diabetes mellitus. METHODS: CV risk factors were collected in 338 young adults participating in a prospective, cross-sectional study. The CV parameters collected included intima-media thickness, peripheral arterial stiffness by brachial distensibility, and myocardial strain and strain rate. General linear models were constructed to determine if vascular structure and function measures were independently associated with myocardial strain and strain rate. RESULTS: A linear relationship was found between global longitudinal strain obtained from the four-chamber view and global strain rate in systole and carotid intima-media thickness (four-chamber global longitudinal strain: ß = 3.0, CV risk factor-adjusted R2 = 0.34; global strain rate in systole: ß = 0.0053, R2 = 0.21; P ≤ .0001) and between four-chamber global longitudinal strain and lower brachial distensibility (ß = -0.42, R2 = 0.22; P < .001). CONCLUSIONS: Adverse changes in vascular structure and function are simultaneously present with reduced myocardial systolic function.

Loss of WISP-2/CCN5 signaling in human pancreatic cancer: a potential mechanism for epithelial-mesenchymal-transition.

The objective of this study was to explore the pathophysiological relevance of WISP-2/CCN5 in progression of human pancreatic adenocarcinoma (PAC). We found WISP-2/CCN5 mRNA and protein expression was faint and sporadic in PAC and detected in only 8.7-20% of the samples with varying grades as compared to adjacent normal and chronic pancreatitis samples where expression was very high in the ducts and acini. Colocalization studies in tissue-microarray slides revealed WISP-2/CCN5 mRNA loss was associated with p53 overexpression in PAC. Like tissue samples, p53 mutant-PAC cell lines show loss of WISP-2/CCN5. Moreover, functional analysis studies demonstrate exposure of pancreatic cancer cells to WISP-2/CCN5 recombinant protein enhances mesenchymal-epithelial-transition (MET). Collectively, we suggest WISP-2/CCN5 silencing may be a critical event during differentiation and progression of PAC and mutant p53 is possibly an important player in pursuing this episode.

Structure-Based Screen Identification of a Mammalian Ste20-like Kinase 4 (MST4) Inhibitor with Therapeutic Potential for Pituitary Tumors.

Pituitary tumors of the gonadotrope lineage are often large and invasive, resulting in hypopituitarism. No medical treatments are currently available. Using a combined genetic and genomic screen of individual human gonadotrope pituitary tumor samples, we recently identified the mammalian sterile-20 like kinase 4 (MST4) as a protumorigenic effector, driving increased pituitary cell proliferation and survival in response to a hypoxic microenvironment. To identify novel inhibitors of the MST4 kinase for potential future clinical use, computational-based virtual library screening was used to dock the SelleckChem kinase inhibitor library into the ATP-binding site of the MST4 crystal structure. Several inhibitor candidates were identified with the potential to bind with high affinity. Using a TR-FRET in vitro recombinant kinase assay, hesperadin, initially described as an Aurora kinase inhibitor, exhibited potent inhibition of the MST4 kinase at nanomolar concentrations. The LßT2 gonadotrope pituitary cell hypoxic model was used to test the ability of this inhibitor to antagonize MST4 actions. Under short-term severe hypoxia (1% O2), MST4 protection from hypoxia-induced apoptosis was abrogated in the presence of hesperadin. Similarly, under chronic hypoxia (5%), hesperadin blocked the proliferative and colony-forming actions of MST4 as well as the ability to activate specific downstream signaling and hypoxia-inducible factor-1 effectors. Together, these data identify hesperadin as the first potent, selective inhibitor of the MST4 kinase with the capacity to block pituitary tumor cell growth in a hypoxic microenvironment.

Epidermal growth factor receptor: is a novel therapeutic target for pancreatic cancer?

Expression of epidermal growth factor receptors (EGFR) is exaggerated in pancreatic adenocarcinoma and activation of EGFR appears to have an important role in the growth and differentiation of this and in other tumors. Therefore, blockade or inactivation of EGFR by monoclonal antibodies or by tyrosine kinase inhibitors has significant potential as an effective anti-cancer therapy. One of the very recent significant developments in the field of molecular biology involves the use of antisense of EGFR or EGFR gene silencing in pancreatic cancer cells as a potential targeted therapy for patients with pancreatic adenocarcinoma.